Apparatus for interlacing multifilament yarn



Feb. 11, 1969 F MOCUTCHAN, JR 7 3,426,406

APPARATUS FOR INTERLACING MULTIFILAMENT YARN Filed May 18, 1967 FIG.!

INVENTOR FRANK MCCUTCHAN JR.

ATTORNEY United States Patent Claims ABSTRACT OF THE DISCLOSURE An improved jet for interlacing and plying multifilament yarn comprising a body member, a yarn passageway through the body along a straight axis, and at least one pair of opposed fluid conduits having a common longitudinal axis which intercepts and is perpendicular to the axis of the yarn passageway, the yarn passageway being further characterized by having a cross section in the vicinity of the fluid conduits corresponding to an ellipse or a rectangle having semicircular ends, the cross section having a width to height ratio within critical limits for improved interlace uniformity and greater fluid efiiciency.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to improved fluid interlacers which impinge opposed jets of fluid on yarn for producing interlaced multifilament yarn of improved interlace uniformity.

Description of the prior art The use of fluid interlacers of this general type for producing interlaced yarn is disclosed in Bunting et al. US. Patents Nos. 2,985,995 and 3,110,151 and in Bunting et al. US. application Ser. No. 485,438 filed Sept. 7, 1965, now US. Patent No. 3,364,537. The utility of the apparatus described in these patents is well known, as shown by the expanding trade acceptance of yarns produced by this equipment in place of twisted yarns. However, a special problem arises in certain fabrics, such as tafletas and satins of cellulose acetate, where appearance uniformity is especially critical. The regions of greatest filament entanglement in the usual alternating pattern of tight and loose interlace sections create noticeable streaks or barr in such fabric. Reducing the average degree of interlace to the point where the tighter sections are no longer evident also reduces the cohesion of the looser sections, allowing the yarn bundle to separate which creates processing problems such as the snagging of filaments in mill equipment.

SUMMARY OF THE INVENTION This invention provides a fluid interlacer for yarn which produces more uniform spacing of maximum interlace points along the threadlines than existing equipment. This invention also provides an interlace jet that requires a smaller amount of interlacing fluid to produce a yarn having a given average level of interlace cohesion. Also provided is an interlacer that produces a yarn having less variation of filament entanglement,

The improved fluid interlacer of this invention comprises an interlacer body having a yarn passageway and a pair of opposed fluid conduits which are positioned within the body to direct streams of high velocity fluid perpendicular to the axis of the yarn passageway. The yarn passageway at the point where the fluid conduits intersect is rectilinear with semicircular ends, oval, or elliptical :in cross section with critical dimensions as specified in the description of the preferred embodiments and the claims. The yarn passageway cross section need not be the same in form throughout its length. The two opposed fluid conduits have a common longitudinal axis and may be circular in cross section or any suitable configuration such as rectangular, oval, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with reference to the drawings which illustrate specific embodiments. In the drawings,

FIGURE 1 is a longitudinal cross section taken along the axis of the yarn passageway of a fluid interlacer of this invention;

FIGURE 2 is a cross-sectional end view taken on line 2-2 of FIGURE 1;

FIGURE 3 is a cross-sectional end view taken on line 2-2 of FIGURE 1, showing another embodiment of this invention;

FIGURE 4 is a diagrammatic illustration of the use of the improved fluid interlacer in a process of successively drawing and interlacing yarn;

FIGURE 5 is an illustration of yarn which has been interlaced by an interlacer of this invention;

FIGURE 6 shows yarn interlaced by an interlacer of the prior art which has a yarn passageway of a circular cross section;

FIGURES 7 and 8 illustrate yarn interlaced in an interlacer in which the ratio of the width W of the oval yarn passageway to the height H of the passageway exceeds the critical limits of this invention.

More particularly, FIGURE 1 illustrates a representative fluid interlacer of this invention which has lengthwise yarn passageway 12 and opposed fluid conduits 13A and 13D. Fluid conduits 13A and 13D have a common longitudinal axis and intercept yarn passageway 12 at right angles such that the longitudinal axis of the fluid conduits and the longitudinal axis of the yarn passageway are perpendicular.

FIGURE 2 illustrates an embodiment of the invention in which the yarn passageway 12 has a rectilinear cross section as defined by a rectangle having semicircular ends.

FIGURE 3 illustrates another embodiment of the invention in which the yarn passageway 12 has a cross section as defined by an ellipse. The performance of the interlacer having the elliptical yarn passageway of FIG- URE 3 is not significantly different from the interlacer of FIGURE 2 having the rectilinear yarn passageway.

In the drawings the height of yarn passageway 12 is indicated by H and is measured along the axis of the opposed fluid conduits 13A and 13D. The width of yarn passageway 12 is indicated by W and measured perpendicularly to each end at the intersection of the axis of fluid conduits 13A and 13D and the longitudinal axis of yarn passageway 12.

The diameter of the fluid conduits 13A and 13D is referred to as F.

Air or other fluid can be supplied to the opposed fluid conduits by a suitable manifold arrangement.

The process of this invention is carried out in conjunction with one or more of the conventional textile operations, such as spinning, drawing, winding, packaging, or the like, thereby taking full advantage of the existing means for forwarding the yarn at controlled positive tension and obviating the need for a separate interlacing step. FIGUERE 4 shows apparatus useful for interlacing as part of the drawing operation. It illustrates the stringup assembly whereby interlacing occurs immediately after drawing and prior to packaging. In accordance with this embodiment, undrawn yarn 27 is withdrawn from package 35, passes through pigtail guide 30, then is passed in multiple wraps about driven feed roll 36 and its associated separator roll 37. From feed roll 36 the undrawn yarn makes one or more wraps about a snubbing pin 38 and is drawn in frictional contact therewith under the urging of draw roll 39 and its associated separator roll 40. Draw roll 39, of course has a higher peripheral speed than the feed roll 36, and the yarn is elongated to several times its original length. From draw roll 39, which serves as the feed point, the yarn passes to interlacer 11, is interlaced, then passes idler roll 32 to package 33 driven by drive roll 34. Conventional reciprocating traversing means (not shown) are usually associated with the windup assemblies.

The process of this invention can also be carried out in conjunction with a spinning operation whereby yarn may be continuously interlaced. FIGURE 8 of Bunting et a1. U.S. patent application Sea. No. 485,438 filed Sept. 7, 1965, now U.S. Patent No. 3,364,537 shows the arrangement of an interlacer in a conventional spinning operation which is also suitable arrangement for the interlacer of this invention.

In any continuous operation, it is of considerable advantage to utilize an interlacer of the self-stringing type. All embodiments shown have stringup slots. In the embodiments of FIGURES 1, 2 and 3, a stringup slot 22 extends the length of the interlacers and permits stringup with a minimum loss of interlacing fluid. The tunbulent action of the fluid in the yarn passageway 12 serves to curtain the stringup slot so that there is little likelihood of the yarn blowing out of yarn passageway 12 through slot 22. In addition, fluid entering the yarn passageway from slot 22 prevents the yarn filaments, during the interlacing process, from contacting the edges of stringup slot 22 and thus snagging the filaments.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention is an improvement in an interlacer of the type disclosed in Bunting et al. U.S. patent application Ser. No. 485,438 filed Sept. 7, 1965, now U.S. Patent No. 3,564,537.

The improvement resides in critical selection of yarn passageway cross section to achieve the unexpected results of greatly improved interlace uniformity and also increased fluid efficiency, i.e. lower fluid requirements at a given degree of interlacing.

Referring to FIGURES 2 and 3 which illustrate embodiments of this invention, the dimension H should be in the range of about 1.4 to about 1.75 times the diameter of the fluid passage 'F. The ratio of the width W to the height H of the yarn passageway should be between about 1.5 to l and 2.2 to 1. The length of the yarn passages may be widely varied, but should not be less than the width W. Preferably, the length of the yarn passageway will be about 2 to times its width W and should normally be not more than times its width. For cellulose acetate textile deniers, the length of the yarn passageway should preferably be from about 0.2 inch to 1.0 inch. The cross-sectional areas of the opposed fluid conduits should be equal to each other at interception with the yarn passageway, and the ratio of the cross-sectional area of the yarn passageway to the area of one of the fluid conduits should be betwen about 4 to 1 and 7 to 1.

It is to be understood that the yarn passage cross section of this invention may be of any shape approximating that of the shapes shown herein while conforming to the major dimensions specified. For example, the rounded ends defined herein by radius R may be approximated by polygons, or the entire cross section may be an ellipse or other non-round assemblage of smooth curves having no reversals of curvature.

The exact mechanism by which the improvement of this invention is obtained is not entirely clear. However, it is believed that the following explanation is correct though, of course, applicant does not intend to be bound by his theory. As explained in U.S. Patent No. 2,985,995, a yarn is efficiently interlaced with a fluid jet when the yarn is first randomly splayed open, forming oppositehand interlace above and below the center line of the jet. The filaments are forced to move in and about each other forming additional interlace until it is no longer possible for the fluid forces to move the filaments; then there is a brief delay while the upstream interlace section moves through the jet before the process repeats itself. It is this periodic action which gives the characteristic short-length variation in yarn cohesiveness along the threadline. The yarn normally spends varying periods of time in the different zones of the yarn channel where fluid velocity and turbulence can be quite different. Therefore, interlace nodes are normally spaced at somewhat random intervals.

Yarn passage dimensions should be as small as practical to conserve interlacing fluid and to concentrate the zone and effect of the controlled fluid turbulence. On the other hand, too small a yarn channel can constrict the filament bundle, preventing the filaments from splaying apart sufiiciently to become adequately intermingled. In the present invention, the fluid force is concentrated by reducing the dimension H from that of the prior art apparatus, yet an adequate cross-sectional area of the yarn passage is maintained or increased for escape of the fluid by increasing dimension -W, thus maintaining high fluid velocity at the points where fluid impinges on the yarn. The increased width W provides additional space for the yarn filaments to become separated sufficiently so that more thorough intermingling is possible.

The use of fluid interlacers having yarn passages whose cross-sectional shape is intermediate between rectangular and round, is disclosed in U.S. Patent No. 2,985,995; however, if the shape of the passage approaches rectangular, yarn tends to escape from the zone of most intense turbulence and dwell in the corners for random lengths of time. This action produces substantial areas of low yarn cohesion which can cause undesirable problems in textile operations. It has been found that the uniform action of this invention can be found only within the narrow range of shapes between rectangular and round which is specified in this invention. The heart of the present invention is the particular combination of shapes and dimensions which produce improved turbulent fluid patterns in the yarn passage to open the bundle sufiiciently for increased intermingling of filaments and yet prevent the yarn from dwelling in low turbulence areas for any substantial length of time.

The following examples illustrate the interlace uniformity of yarns produced with jets of the present invention compared to yarns interlaced with jets of the prior art.

Cellulose acetate yarn is used in the examples for illustration purposes though any continuous multifilament yarn is suitable. In addition, the interlacer is arranged in a conventional spinning process though it could be appr0- priately locate in other positions, such as, in a drawing process (see FIG. 4).

In these examples, the degree of interlace is measured by the testing device described in U.S. Patent 3,290,932. Large pin drop node intervals indicate loW degree of interlace whereas small pin drop node intervals indicate a high degree of interlace. The measurement of variation, 0' defined as n 2 n (a) .2.

Where:

N =the number of observations x=individual observations (10 consecutive pin drop measurements) is calculated from the node interval values of each of the number of samples shown in the tables. Each sample value, in turn, is the average of 10 consecutive pin drop INTERLACE DATA JET TYPE 10a PRIoR ART) node measurements made on a single piece of yarn. Air Node Interval Number Run Pressure of Samples 5 (p.s.1.g.) Avg. (in.) :1

EXAMPLE I II-B 6.5 2.76 0.6056 4s 7. 5 2. 46 0. 3269 48 1. 84 0.4619 48 Jet Identification g 102 116 10 22 .07 0. 0919 48 (Prior Art) (Improved,

Fig. 2 Type) J'EI TYPE 125 (IMPROVED-FIG.2 TYPE Yarn Speed, yds./min 600 600. 6. 2. 63 0.2244 48 Yarn Luster Bright" 7.5 2. 30 0.2009 48 Denier of Yarn 150 1. 63 0. 1175 48 No. of Filaments 40-.. 40. 14 1. 50 0. 1138 48 Yarn Tension ahead of traverse r011, 6.0:b0.5 5.0;l=0.5. 18 1.13 0.0494 48 grams. 22 0. 98 0. 0344 48 Fluid Conduit diameter (F), inches 0.0380 0.0380. aru gole hoisting; incllliesmu .0;6 0.055.

am oewi ,inc es 0.0 6 0.110. Radius of curvature of yarn hole sides 0.038 0.0275. From F above a ll. 15 readily apparent that the d e iiui th width (W), m. 2 4 type 125 et of the present invention 18 substantially better g g g i "1 3 over a wide range of fluid pressures than the 103 jet of g uid o iduit crosst section area in. zgggxjgg--- 1 .5933 the prior art in that the uniformity is much better (lower 3 55, ,3553%: 5 5 gg: 8 a values) for yarn interlaced with the 125 jet at about Yarn hole shape Round Recaaglgular the same degree of interlace (node intervals).

$ 25 The 125 jet of this invention having fluid conduits of a ig g 46% larger cross section than the 116 jet of Example I, also a jet of this invention, produces a yarn having interlace uniformity superior to yarn produced by the 116 jet of Example I. INTERLACE DATA EXAMPLE III JET TYPE 102 PRIOR ART) Air Node Interval Number This example compares the performance of an inter- Run Pressure of Samples lacer of the prior art having a circular yarn hole with an (111-) interlacer of the present invention (similar to FIG. 2) I-A 8.5 2.88 1.63 260 having fluid conduit cross sections 25% smaller than the prior art jet.

JET TYPE 116 (IMPROVED) I-Al 6. 0 2. 75 0. 50 48 Jet Identification 110 124 From the above table it is seen that the prior art ap- Yarn Speed, yds./min 680 680. paratus used 41% higher pressure than the jet of this invention to produce much less uniform interlace which No. of Filaments.-. is highly significant. ZESQQF Am 45 Fluid Conduit Diameter (F), inches gem gtilevg illgl llltz (V130 infihes am 0 e i inc es EXAMPLE II Radius of curvature of sides of This example compares yarn interlaced with jets of the prior art having a round yarn passageway and a jet of the present invention of the type shown in FIGURE 2.

The jets of this example have larger fluid conduits area. (about 46% larger cross section) than the jets of EX- Yam 1116 Shape Round ample I.

INTERLACE DATA Jet Identificatiml JEl TYPE 110 (PRIOR ART) 125 .103 (migrovedl Run Plresssiue, Node Interval (Prior Art) Tgglsg) Avg. (in) v2 Yam Speed, ydsjmin 6O 6OD In A 25 63 00690 24 Yarn Luster- Bigght. i i f h i i tf 4 JET TYPE 124 (IMPROVED) gim ifffiilf??it.? .1?Y?f?i .f 5.0:h0.5 5.03:0.5. III-A1 1s 0. 74 0.00612 48 Air hole diameter (F), inches- 00465.- 0.0465. Yarn hole height (H), inches 0.076. $3 2 5? Z m g- 0462- The improved jet having smaller fluid conduits uses defining the width (W), inches 0.0465 0.0380. considerably less air than the prior art jet to give equiva- Rattm H m F M4 3 lent average interlace. Ratio, 1: 2.13.1. Fluid Conduit Cross Section Area, in. 1.698Xl0' 1.698X10'3. Yarn Hole Cross Section Area, in. 6.793X10'3 11.137X10-3. EXAMPLE 1V Ratio of Yarn Hole Area to Fluid Conduit Area 4.0:1 6.56:1. Yarn Hole Shape Round Rectangular In this example the elfect on yarn interlace of 1n- $2 12 creasing the ratio 'of yarn hole width W to height H to a g ndszgsee level outside the critical limits of the invention is demonstrated.

Jet Identification (Improved) Yarn speed, yds./rnin 680 680. Yarn Luster DulL Dull. Denier of Yarn- 450... 45 No. of Filaments 120.-- Yarn Tension Ahead of Traverse Roll, 28x24 ems. Fl u id Conduit Diameter (F), inches 0.0625 0.0625. Yarn Hole Height (H), inches 0.087 0.100. Yarn Hole Width (W), inches 0.210 0.162. Radius of curvature of sides of yarn hole 0.435 0.050.

defining the (W) width, inches. Ratio H to F Ratio W to H 1. Fluid Conduit Cross Section Area, 111.... 3.067X-L.-. 3. 67X10- Yarn Hole Cross Section Area, in? 16.64X10-L... .05X10- Rastrio Yarn Hole Area to Fluid Conduit 5.42:1 4.58:1.

ea. Yarn Hole Shape Fig. 2 Fig. 2.

INTERLACE DATA JET TYPE 130 Air Node Interval Number Run Pressure of Samples (p.s.i.g.) Avg. (in.) a

IV-A 17 976 02948 24 JET TYPE 124 IV-Al 17 790 01167 20 EXAMPLE V In this example the performance of an interlacer having an elliptical yarn passageway similar to FIGURE 3 is compared to the performance of a prior art jet having a round yarn hole.

Jet Identification 126 103 (Improved) (Prior Art) Yarn speed, yds/min.

art jet (Run V-Al) and has 33% more interlace in spite of the fluid pressure being 70% lower.

The elliptical hole jet (Run V-B) uses about 50% as much air as the prior art jet (Run V-Al) to make a more uniform yarn having about the same degree of interlace.

EXAMPLE VI This example shows the effect of increasing the ratio of yarn hole width W to height H to a level outside of the critical limits of this invention.

Jet Identification Yarn speed, yds./min 680 680. Yarn Luster. Dull Dull Denier of Yarn 150 150. No. of Filaments 40 40. Yarn Tension Ahead of Traverse Roll,

grams 7:1:1 7:1:1; Fluid Conduit Diameter (F), in. 0.0465 0.0465. Yarn Hole Height (H), inches 0.076..- 0.076. Yarn Hole Width (W), inches 0.210 0.120. Radius of curvature of sides of yarn hole 0.038 0.038.

defining the Width (W), in. Ratio H to F 1 63:1 1.63:1. Ratio W to H z 1.57421. Fluid Conduit Cross Section Area, in. 1.698X10- 1.698X10- Yarn Hole Cross Section Area, in. 15.48X10-L 7.88X1IH. Raxtio Yarn Hole Area to Fluid Conduit 9.12:1 4.65:

rea. Yarn Hole Shape Fig. 2 Fig. 2.

INTERLACE DATA JET TYPE 128 Air Node Interval Number Run Pressure of Samples (p.s.i.g.) Avg. (in.) a

VI-A 14 2. 78 12. 66 48 VI-B 22 1. 18 0. 1044 48 JET TYPE 114 The Type 114 jet is far superior to the Type 128 jet havlng an excessive W to H ratio in both efiiciency and uniformity of interlace. The theory seems to be, though Yam Luster 45 applicant does not intend to be bound by any theory, that Denier the large W to ratio of the Type 128 jet affords too No. ofilarn euts.. large a probability for the yarn to move in and out of Yarn tension ah gramsareas of low turbulence at the sides of the yarn hole, or Fluid conduit diameter (F), in 0.0465 ta Yam Hole Height m 0.076 3; there, tol be efficiently and uniformly interlaced. Yarn Hole Width w in 0.120 5 inter acefi wi et 128 (having an excessive Radius oteurvature of side o y hole 0-030 W/H) is shown in FIGURES 7 and 8 corresponding to defining the width (W), in. R VI A d B h Radius of curyature defining portion of 0.090- 0.0465 an VI- W as yarn from the Type 114 g 1 gnio :%d1 c fluid condults, 1 634 et (interlaced at 18 p.s.i.g.) is shown in FIGURE 5. For gf gg d 0 Ar :25 0 Q j comparison, yarn interlaced with a round yarn hole jet ui on ui res n ea,i 1. 8X1 Yarn Hole Cross Section Area, in)... 7.16 10- 6. (Type 103 Jet of Examples I.I IV V) 18 Shqwn In A r Yam Hole Area to Fluid Conduit 43mm FIGURE 6. Both the more uniform spacing of the tightest 88,. o Yam holeshape Approx Round secti ns of entanglement and less variation of filament ejjipse, entanglement intensity between points of maximum enstanglement is evident from yarn interlaced with an oval hole et of this invention (FIG. 5). INTERLACE DATA JET TYPE 126 EXAMPLE VII Air Node Interval Number Run Pressure of Samples Jet Identification (p.s.i.g.) Avg. (in.) a

127 114 V-A is 0.67 0.0166 40 (Reetan ular (Oval Hole, V-B 10 1.08 0. 0321 40 E015 Fig. 2)

Yarns eed, ydsJmin JET TYPE 103 1Y)'arr i IFufstler eniero arn--. 1 V-Ai 20 1. 06 0.0779 24 N0. of Filaments 4o- 43.

Yaiirnll Tension Ahead of Traverse 7i1. 7;i=1. igmmsx From the above data it is evident that the elliptical yarn l g t i in .0 6. hole jet exhibits outstanding performance as compared gifi 3 5 g t 3% 3%.?-

Radius at corners, Yarn Hole, in 0:001

sides forming width (W).

'IABLE-C0ntlnued J et Identification 127 114 (Rectan ular (Oval Hole, H015 Fig- JET TYPE 114 VII-2 14 0. 94

The Type 114 oval-hole jet of this invention produces much more uniform interlace and a higher degree of yarn to separate and interlace filaments of the yarn, said opposed conduits having a common longitudinal axis which intersects the axis of the yarn passageway and is perpendicular thereto; and means for supplying cfluid to said opposed conduits; wherein the improvement is a yarn passageway having an elliptic cross-section which is further characterized as having a width to height ratio within the range from about 1.5 :1 to about 22:1 and sides, defining the width of said yarn passageway, which are the arc of a circle, said height of the yarn passageway being measured along the axis of the fluid conduits and said width being measured perpendicularly to the axis of the conduits and the axis of the yarn passageway at the intersection of the two axes.

2. Apparatus as defined in claim 1 wherein the yarn passageway cross section at interception with the fluid conduits is a rectangle having semicircular ends.

3. Apparatus as defined in claim 1 wherein the yarn passageway cross section at interception with the fluid conduits is an ellipse.

4. Apparatus as defined in claim 1 wherein the crosssectional areas of the opposed fluid conduits are equal to each other at interception with the yarn passageway and the ratio of the cross-sectional area of the yarn interlace at equivalent conditions than does the rectangu- 25 passageway to the area of a fluid conduit is from about lar hole jet.

4:1 to about 7:1.

TABLE I.CRITICAL DIMENSIONS OF JETS OF THIS INVENTION REFERRED TO IN THE EXAMPLES Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not 5. Apparatus as defined in claim 1 wherein the crosssectional areas of the opposed fluid conduits are equal to each other at interception with the yarn passageway limited by the specific illustrations except to the extent 45 and are circular, the ratio of the height of the yarn defined in the claims.

What I claim is:

1. The improvement in yarn-interlacing apparatus of the type comprising a fluid interlacer body member, a

yarn passageway through the body member extending 50 along a straight axis; feeding and withdrawing means for continuously forwarding the yarn at controlled positive tension along the axis through said passageway; directly opposed fluid conduits into said passageway in the body passageway to the diameter of a fluid conduit is from about 1.4:1 to about 1.75:1.

References Cited UNITED STATES PATENTS 3,364,537 1/1968 Bunting et al.

MERVIN STEIN, Primary Examiner.

member for impinging fluid against opposite sides of the 5 IRA C. WADDEY, 111., Assistant Examiner. 

